Bug in latest version?

I bought a Pure i9 almost a month ago. I was impressed with how solid and well-built it was. I have had a lot of robotic vacuum cleaners since we got our first one, a Trilobite, almost 16 years ago and nobody, besides the trilobite, has felt as solid as this one.
Unfortunately, my joy disappeared when I tried it. First, it behaves reasonably sensibly, but the longer it clean the more 'stupid' it becomes. It is clearing for a while in, for example the living room and suddenly break away to the hall, stand there and think a little, drive a little on a surface it has already been on, then return to the living room. It can clean the same surface several times and skip other surfaces. Much of the time it stands still and thinking, spins around and is obviously lost. The funny thing is that it always finds back to the charging station, though it does not seem to know where it is or has been. It also seems to be 'clumsy' when it gets lost. Run into furniture and other things repeatedly.
There must be something wrong with the software. It has the latest fw. I have difficulty understanding that it has received such good reviews with this software.
Is it some bug in the lates version?
Even the old Trilobite was smarter than this.
Unfortunately, I must probably return the robot to the store because, as it now works, it is completely useless.

The floor is oak parquet in all the rooms with some carpets with short pile. The rooms have regular windows so there are none that go from floor to ceiling or are unusually large. No mirrors. The layout is very open and not complicated in any way. I want to say that we have one of the most robotic-friendly homes you can have.
I can't believe it the odd behavior depends on any external factors. They are the same all the time while the robot works worse the longer it is cleaning. After each time it pauses for charging, the worse it works.
What could affect is that the charging station is placed in a long narrow hallway (6 x 1.5 m) and it does not pass it except at the beginning of the cleaning cycle and every time it is to be charged.
The store where I bought the robot offers that I may return it within 30 days. These days are now running out. After reading the thread about the problems with the robot's behavior that have been since october I dare not hope it will be fixed in a few days, so I have decided to return it to the store. I am not happy to do that because I like how well built it is mechanically. In comparison with Pure i9, the competitors feel like toys.
But if it has no functioning software then it does not work how well built it is otherwise. Therefore, unfortunately, I cannot help with screenshots etc.

D7 feels more primitive and it doesn't move as carefully and smoothly as i9. It behaves like a Catepillar. It is also not as good mechanically built. I have only used it once and then managed to clean 90 square meters without any problems. Something that i9 did't during the month I had it. I'll use D7 a few times before I make any conclusions.